Synthesis and Structure−Activity Relationship of 4-Substituted 2-(2-Acetyloxyethyl)-8-(morpholine- 4-sulfonyl)pyrrolo[3,4-<i>c</i>]quinoline- 1,3-diones as Potent Caspase-3 Inhibitors

Synthesis, biological evaluation, and SAR dependencies for a series of novel 1,3-dioxo-2,3-dihydro-1H-pyrrolo[3,4-c]quinoline inhibitors of caspase-3 are described. The inhibitory activity of the synthesized compounds is highly dependent on the nature of 4-substituents on the core scaffold. 4-methyl-and 4-phenyl-substituted derivatives, which were the most active compounds within this series, inhibited caspase-3 with IC50 of 23 and 27 nM, respectively.